NEMERTINES OF PLYMOUTH SOUND. 23 
Family LINEIDA, McIntosh. 
A. AMICRURZ, Biirger. 
Caudal process absent. 
Genus LINEUS, Sowerby. 
23. L. Lonatsstmus (Gunn, Sowerby). 
L. MARINUS, McIntosh. 
Not very abundant. Occasionally dredged at the Yealm among 
Phallusia and other Ascidians, and in the deeper water outside the 
Breakwater. Sometimes found shore-hunting during very low tides 
among the roots of Laminaria. No specimens have been met with 
of the size given by McIntosh, the largest not being more than six 
feet long, while the majority are very much less. Apparently a 
northern form, as it occurs on the coasts of Norway and Belgium 
and the Atlantic coasts of France, but not in the Mediterranean. 
24, L. opscurus, Desor. 
L. GESSERENSIS, McIntosh. 
L. sANGUINEUS, McIntosh. 
I. GESSERENSIS, Joubin. 
By far the commonest Nemertine in the Sound. It is to be found 
everywhere between tide-marks. Joubin describes five colour 
varieties: (a) deep blue and black; (b) deep olive-green; (c) pure 
green; (d) green and red; and (e) red. All these varieties, with the 
exception perhaps of the third, I have met with in the Sound, but I 
have not noticed that any particular habitat is characteristic of any 
individual variety. In common with Hubrecht and Joubin, I regard 
the L. gesserensis and sanguineus of McIntosh as varieties of the 
same species. 
Neither Hubrecht nor Birger has found this species in the 
Mediterranean, but Joubin appears to have obtained it at Porte 
Vendres, and Dewoletzky at Trieste. It is, however, like L. longis- 
simus, a northern form, though it has a greater southern extension 
than the latter. 
According to McIntosh the breeding season lasts from January to 
May. Mr. Garstang tells me that during the present year he has 
found eggs and ripe specimens as early as January, and they are still 
(March) to be obtained. 
